Fixing those annoying heat spots in your KHS blow molding lines
Ever pull a batch of PET bottles off the line and see those weird pearlescent streaks or, worse, burnt spots? It’s frustrating. Usually, it just means your oven isn’t heating the preforms evenly. When the heat is all over the place, you get wonky wall thickness and distorted bottles. We’ve seen this a thousand times. That’s why we built our infrared (IR) lamps to be simple, direct drop-in replacements. They just fit, and they fix those thermal gaps.
Getting the heat right
Most Krones-style heaters use shortwave IR. The trick is in the details—the quartz purity and how the filament is actually shaped. Cheap tubes often have “cold spots” right near the electrodes. It’s a common headache. We handle this by precision-tuning the winding density so the heat stays consistent from one end to the other. Now, I know you want to keep your line speeds high, which means you need a lot of wattage. But there’s a catch. If you just cram more power into a short tube, you’re asking for a burnout. We balance the voltage and wattage so you get the heat you need without stressing the quartz envelope to the breaking point.
The nitty-gritty on fit and feel
These lamps use heavy-wall quartz glass because oven airflow can be brutal. They’re built to take a beating. And we didn’t overcomplicate the install. We use standard R7s or SK15 connectors. You just plug them in and go. No annoying adapters, no “making it work.” Depending on what your preforms are made of, you might want our coated versions. These shift the emission spectrum to better match PET. Instead of wasting energy heating up the air around the bottle, the heat actually sinks into the plastic. It’s just more efficient.
A few things to keep in mind
High-output lamps put out a massive amount of heat, but they also pull a lot of power. If you’re upgrading to higher-wattage tubes to push more volume, do yourself a favor: check your breakers and wiring gauges first. You don’t want a tripped panel in the middle of a run. Also, keep an eye on your cooling system. More heat in the oven means your cooling has to work harder to keep the machine frame from warping. Just a heads-up.